mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-11-23 07:58:09 +00:00
60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
/*
|
|
* CRC32 checksum
|
|
*
|
|
* Copyright (c) 1998-2003 by Joergen Ibsen / Jibz
|
|
* All Rights Reserved
|
|
*
|
|
* http://www.ibsensoftware.com/
|
|
*
|
|
* This software is provided 'as-is', without any express
|
|
* or implied warranty. In no event will the authors be
|
|
* held liable for any damages arising from the use of
|
|
* this software.
|
|
*
|
|
* Permission is granted to anyone to use this software
|
|
* for any purpose, including commercial applications,
|
|
* and to alter it and redistribute it freely, subject to
|
|
* the following restrictions:
|
|
*
|
|
* 1. The origin of this software must not be
|
|
* misrepresented; you must not claim that you
|
|
* wrote the original software. If you use this
|
|
* software in a product, an acknowledgment in
|
|
* the product documentation would be appreciated
|
|
* but is not required.
|
|
*
|
|
* 2. Altered source versions must be plainly marked
|
|
* as such, and must not be misrepresented as
|
|
* being the original software.
|
|
*
|
|
* 3. This notice may not be removed or altered from
|
|
* any source distribution.
|
|
*/
|
|
|
|
/*
|
|
* CRC32 algorithm taken from the zlib source, which is
|
|
* Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler
|
|
*/
|
|
|
|
#include "crc.h"
|
|
|
|
static const uint32_t crc32tab[16] = {
|
|
0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, 0x76dc4190,
|
|
0x6b6b51f4, 0x4db26158, 0x5005713c, 0xedb88320, 0xf00f9344,
|
|
0xd6d6a3e8, 0xcb61b38c, 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278,
|
|
0xbdbdf21c
|
|
};
|
|
|
|
/* crc is previous value for incremental computation, 0xffffffff initially */
|
|
uint32_t crc32(const uint8_t *data, uint32_t length, uint32_t crc)
|
|
{
|
|
for (uint32_t i = 0; i < length; ++i) {
|
|
crc ^= data[i];
|
|
crc = crc32tab[crc & 0x0f] ^ (crc >> 4);
|
|
crc = crc32tab[crc & 0x0f] ^ (crc >> 4);
|
|
}
|
|
|
|
// return value suitable for passing in next time, for final value invert it
|
|
return crc/* ^ 0xffffffff*/;
|
|
}
|